US915 can join but no uplink being received?

Hi @Bocar and Chirpstackers,

I am switching my end-node from AS923 to US915, the end-node can send Join Request and receive Join Accept successfully. After joining, it tries to send the Uplink packets but it could not be seen on the Gateway. I’ve already modified to send the UL exactly the same as Join Request’s channel but it still does not work?

Can you please guide me on how to solve this problem?

Thank you all,


Did you modify the channels on the gateway configuration itself? There are specific channels for uplinks and downlinks and I had to set the bands in my gateway’s configuration (using the Tektelic Kona Micro) US channel bands

I am wondering if it’s trying to uplink on a channel that’s not being listened on?

Thanks @John_Roesler,

I configured Multitech to use sub-band 8, and used a fixed channel (56) to send both Join Request, and the Uplink. But only Join Request can be received by the gateway. I could not figure out the problem?

Any idea?

Are you able to see if a join accept is being sent from ChirpStack? And then, are you able to see if uplinks are being sent by your device, and if any errors are occurring (in ChirpStack logs)?

I can see a Join Accept on both Chirpstack and my end-node, the problem is after joining, I try to send the first uplink with NULL data on the same channel with Join Request but It could not be seen on Chirpstack?

I could not understand why the Joint Request can be sent out of my end-node, but the uplink can not. Got this struggling for two weeks already?


Are you able to see anything in the logs for ChirpStack network server or application server? I don’t believe you can send an uplink with NULL data - looking at version 1.0.2 (haven’t checked other versions) the payload must be at least 1 byte.